1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 File: linux/posix_acl_xattr.h 4 5 Extended attribute system call representation of Access Control Lists. 6 7 Copyright (C) 2000 by Andreas Gruenbacher <[email protected]> 8 Copyright (C) 2002 SGI - Silicon Graphics, Inc <[email protected]> 9 */ 10 #ifndef _POSIX_ACL_XATTR_H 11 #define _POSIX_ACL_XATTR_H 12 13 #include <uapi/linux/xattr.h> 14 #include <uapi/linux/posix_acl_xattr.h> 15 #include <linux/posix_acl.h> 16 17 static inline size_t 18 posix_acl_xattr_size(int count) 19 { 20 return (sizeof(struct posix_acl_xattr_header) + 21 (count * sizeof(struct posix_acl_xattr_entry))); 22 } 23 24 static inline int 25 posix_acl_xattr_count(size_t size) 26 { 27 if (size < sizeof(struct posix_acl_xattr_header)) 28 return -1; 29 size -= sizeof(struct posix_acl_xattr_header); 30 if (size % sizeof(struct posix_acl_xattr_entry)) 31 return -1; 32 return size / sizeof(struct posix_acl_xattr_entry); 33 } 34 35 #ifdef CONFIG_FS_POSIX_ACL 36 struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns, 37 const void *value, size_t size); 38 #else 39 static inline struct posix_acl * 40 posix_acl_from_xattr(struct user_namespace *user_ns, const void *value, 41 size_t size) 42 { 43 return ERR_PTR(-EOPNOTSUPP); 44 } 45 #endif 46 47 int posix_acl_to_xattr(struct user_namespace *user_ns, 48 const struct posix_acl *acl, void *buffer, size_t size); 49 static inline const char *posix_acl_xattr_name(int type) 50 { 51 switch (type) { 52 case ACL_TYPE_ACCESS: 53 return XATTR_NAME_POSIX_ACL_ACCESS; 54 case ACL_TYPE_DEFAULT: 55 return XATTR_NAME_POSIX_ACL_DEFAULT; 56 } 57 58 return ""; 59 } 60 61 static inline int posix_acl_type(const char *name) 62 { 63 if (strcmp(name, XATTR_NAME_POSIX_ACL_ACCESS) == 0) 64 return ACL_TYPE_ACCESS; 65 else if (strcmp(name, XATTR_NAME_POSIX_ACL_DEFAULT) == 0) 66 return ACL_TYPE_DEFAULT; 67 68 return -1; 69 } 70 71 /* These are legacy handlers. Don't use them for new code. */ 72 extern const struct xattr_handler nop_posix_acl_access; 73 extern const struct xattr_handler nop_posix_acl_default; 74 75 #endif /* _POSIX_ACL_XATTR_H */ 76